Plastic Bearings
When 67-year-old Indian aviator, Dr Vijaypat Singhania recently flew to 69,852ft and set a new world altitude record for a hot air balloon, one of the technologies that helped him to do it was the use of plastic bearings.
Plastic bearings were a crucial component in the balloon’s pressurised capsule, and injection moulded plastic bearings were used. A conventional hot air balloon has a fabric valve in the top, opened by the pilot pulling a string when he requires the balloon to descend – not possible in a pressurised capsule.
Two hand wheels inside the capsule were connected to a drum on the outside of the capsule via a shaft mounted in plastic bearings able to stand up to temperatures of -60C at 70,000ft.
However, the temperature expected on the ground before take-off was +38 degrees C – but the temperatures were no problem for the high performance plastic bearings.
It’s a feat that could not have been attempted before the invention of plastic bearings. Modern engineering plastics have overtaken traditional materials such as wood and metal in a wide range of engineering applications – and in particular in wear-part or plastic bearing applications.
When engineers are choosing plastic bearings for a particular plastic bearing application, the most important factor in choosing plastic bearings is their ability to withstand wide variations in load over a long period of time.
Despite this plastic bearings will still operate with good reliability, even through the maintenance routine can be regarded as unpredictable. Plastic bearings are regarded by experienced engineers as having a “fit and forget” ability, which makes plastic bearings an important and cost-effective application.
Most rotating elements in industrial machinery currently rely on one or more bearings – often plastic bearings – for their effective operation. Plastic bearings are often believed to be a one size fits all product, but this is far from true – many specialised plastic bearings are available.
The advantage of these plastic bearings to engineers and companies is that they not only boost the performance of machinery where the plastic bearings are fitted, but also create improvements in the machinery’s service life, where the plastic bearings can help to reduce downtime and maintenance costs.
A further practical advantage of plastic bearings is that they can be engineered to be low friction, meaning that the plastic bearings can reduce friction in applications such as motors, pumps and conveyors. The plastic bearing benefit here is a reduction in energy consumption, which means once again the plastic bearings are saving the user money.
Plastic bearings also have many advantages over steel bearings. First, plastic bearings are very lightweight compared to steel, which means plastic bearings are a real boon to people who want to design low-weight equipment but want to keep performance high.
Plastic bearings are also free of the need of lubricants. Unlike steel, plastic bearings are naturally resistant to corrosion and damage from chemicals, which makes plastic bearings extremely suitable form applications where they may be subjected to aggressive chemicals such as cleaning fluids or dampness.
This can be important if the machine is used in, for instance, the food industry where regular rigorous cleaning is extremely important but can cause machinery to corrode. Plastic bearings can withstand such regular dousings of chemicals without being damaged.
Plastic bearings are also very resistant to wear and fatigue, which ensures that machinery with plastic bearings will have a long and low-maintenance life in service.
It’s not surprising that plastic bearings can be used in an extremely wide range of applications and machinery, ranging from sports equipment and theme park attractions, to printing presses, office equipment, home equipment and cranes. For instance, plastic bearings have been used in giant roller-coasters because of their ability to help damp vibration – crucial to the safe running of the big dipper and the comfort of its passengers.
In such applications where accessing a component is difficult after it has been installed, the lubrication-free and non-corrosive properties of plastic bearings make life a lot easier.
Plastic bearings also have many off-shore and marine uses, where once again the anti-corrosive properties of plastic bearings provide resistance to sea water and keep maintenance and replacements needs at a minimum.
Plastic bearings are also being put to good use in developing countries – their longevity and durability are particularly valued in areas where replacement parts are hard to come by. For instance, donkey carts have been designed using plastic bearings in their axles – these plastic bearings can be made out of PVC water pipe.
Even the newest of technologies such as solar power are making use of plastic bearings. Plastic bearings play an important role in systems that turn photovoltaic energy-producing plates constantly to face the sun – the plastic bearings fulfil the requirement to be hard-wearing while at the same time proof against the extreme weather temperatures that can be experienced. Plastic bearings are also strong enough to resist the grinding effect of sand where it is sucked into machinery.
Plastic bearings can be made of a variety of plastics to suit individual requirements – for instance, thermo-plastics are used in applications where heat will be an issue.
One further benefit of using plastic bearings in applications is that plastic bearings do not create much noise while the machinery is in operation – important for design engineers working on applications where low-noise is a requirement.
They are clean and neat in appearance, and also do not contaminate their surroundings unlike bearings made of some other materials. Plastic bearings are also low-cost in their own right, as well as providing many cost-saving benefits during the service life of the machinery where they are installed.
When you consider the benefits plastic bearings such as those provided by Bluemay offer, it’s not surprising that they are a modern-day success story. If you use machinery in your daily life, these days you can practically guarantee that plastic bearings will be helping it on its way to a long, maintenance-free and smooth running life.